How to network unlock

It depends on the carrier now >_<. Metro/T-Mo uses an app and does not use a code; AT&T PREPAID stole the T-Mo app method on newer phones, so it's a crapshoot BUT usually pretty easy to tell because it has an app called "Device Unlock," but I assume anything new is the app just in case. Verizon is 60 days; for LTE phones, it's usually ~1 year but that's old phones. FCC licensing put Verizon in their place :-).

Sprint is dead, and most of their phones are hard-locked except the GSM part, which was not used here; it was an "international unlock" because they did it to keep their grip on the device. A lot (if not 90%+) of the "non-unlockable" GSM phones went out with the US 3G sunset, so it doesn't matter since they're officially eWaste anyway. For the survivors that predated the 2015 CTIA deal, the same issue applies: T-Mo can't fix boneheaded ideas from years ago.

There was also another ugly issue: anything post-CTIA that can be fully unlocked is a pain because of Sprint's unlock policies; it has always been faster to pay third-party companies to do the dirty work with the IMEI# for you. Of course, this assumes the Sprint radio firmware isn't a PITA to get going on other cellular networks (or they use T-Mo towers to negate the issue).

This may not be as true under T-Mo, but you can only fix their toxic unlock policies—not their hard-locked cell radios, for instance. Expect trouble with an active EIP balance. 3rd parties still have to do the dirty part for you.

The other issue with Sprint phones that makes them worth more dead is things like VVM were so custom on Sprint's old network, you probably can't keep it; you need to do VM like it's a flip phone.

This doesn't apply to you (thankfully), but it's yet another problem that comes up :-(. LG... Their Sprint phones had custom ROMs and custom cellular radio firmware; almost none of them carry well; they tend to be haphazardly bad on other networks. SprintxLG phones are ALL eWaste :-(. Sprint SKU? Steal the screens and parts off of it and get rid of the cursed motherboard!!! LG bent backward for Sprint and paid the price later... As if they care, they just cared about their bottom line and sales. MOST CARRIERS DO NOT WANT TO DEAL WITH FORMER SPRINT BUILD LGs FOR GOOD REASON; COST AND NETWORK TROUBLE! Some only take them on the condition when they utterly fail, it's YOUR problem.

Generally, Any Sprint phone over three years old is a mess, too. They had their own 5G bands which T-Mo did not use, so they permanently got nerfed into "4G" devices. They wanted the spectrum, not the crappy nightmare phones. However, Sprint phones are excellent trade-in devices unless the phone has standard 5G bands and can be saved from their death grip nightmare (rare).

T-Mo uses the app on nearly all of its phones and pre- and postpaid plans, using the same method as AT&T PREPAID. I have less knowledge of those because the phone is probably ineligible as I got it, and I need to start over on the clock, so I need to pay someone to speed it up. No thanks. Postpaid? NOT HAPPENING: 3.5 years is out of the question, or they are also account-locked as a bonus issue. Verizon automatically unlocks it in 60 days now.

The process per OEM varies. For example, Motorola has many phones that use a "network unlock" procedure like T-Mobile, but it can also vary per original carrier. For example, an ISP MVNO may use a code, while the big three may go either way. Most Motorola phones are so cheap that most people buy them outright. $4-600 seems to be the magic number for phones primarily sold unlocked from the start, or ~$7-800 for most flagships. Apple is just Apple; expect to pay at least $1k+ for a not SE.

Other manufacturers are even less consistent, like Samsung. T-Mo Samsungs use the "Device Unlock" app or "Network unlock" method, while AT&T can choose between a code and a "Network unlock" menu. I know the S20 uses codes, but those phones are too old for me now. The S21-present can go both ways, and I do not have a direct answer because they have a balance in most cases.

Google uses a profile like Apple to do this and puts a carrier-specific ROM on the device; much less awful since it's a quick call or you have to use an app, and it's just done since the carrier just requests that it be dropped on Google's side. The problem with these current prices is I may never know outside of those few cases with these new contracts running so long... 3-3.5 years!!!

At this point, the only way I have a shot at it is if I play the waste bin lottery with family and get my hands on an S22/22+ (which I know is paid off, so I can USE IT) or a phone, which isn't EOL from the same lineup. Once I can do a few, I'll have a better idea. The problem is that they don't buy phones often now due to the cost; by the time I get to them, I'm rebuilding them with used parts due to cost vs. good examples, and the updates stopped a long time ago. I can't squeeze blood out of a stone or make a moist napkin not crumple into shreds, so how can I make a screen my dad broke yet again viable on a 2.5+-year-old phone, which is 40-50% of the way to a good one?

Screens ALWAYS TOTAL OUT SAMSUNG DEVICES, which both are loyal to. As of late, I've only been getting them when the screen is flickering, the glass is busted, and the phone is no longer worth fixing (mostly). See here: How hard is it to restore the water resistance?. I will never have an answer for this dilemma because I do not finance phones; I'll put off the purchase until I can pay directly online (or at Best Buy). For the iPhones, I only buy them at Apple stores. Sometimes, I get them used if the price is right, but I will walk away if it isn't the factory-unlocked version.

The issue as to why I do not know is people are keeping their phones longer now, and when they hit the market, they are worn out, old, or destroyed. This is even with family I know throwing them away like trading cards with a high score of 7 broken phone screens. As a result, I will likely never know with (then current) AT&T postpaid procedure for at least a few years. I am genuinely at the point where I just do not care to find out as I am not waiting 3 years for someone to pay off a carrier-locked phone to unlock it and get the answer, and it may change again. I'm done with this game... You win carriers.

The cost of phones and the length of EIPs make carrier-locked phones only used by two camps: carrier loyalists and companies leasing and dumping them. Everyone else pulls their card out and pays cash for their phone, carrier UNlocked. Same phones anyway, sans the carrier BS.

They use the support line to catch old-timers who don't know better now, yet dump them at the device's OEM. Service centers have been dead for years.

The rest of us who buy used? We've responded by not skipping ANY locked device on the used market. Either sort this crap out yourself or look for someone else. They have no resale now. Again, the mission is accomplished if you're a carrier franchisee or a corporate store. I've been there: I tried to unlock 3 AT&T PREPAID LTE phones (Moto, one was delayed, and the other was instant). LG was just as bad... 1 good, one delayed; that was it for me. I used to be okay with locked phones with minimal bloatware if the unlock was cheap, but 2 of 3 being a PITA made my mind not to buy it that way. I did look into a used S20 for science purposes, but 3 of them I checked out still had a balance :-(. Nope...